Cement-gun apparatus.



IN ENTOFI. W 6 m Patented Apr. 24, 1917.

J. F. JOHNSON.

CEMENT GUN APPARATUS.

APPLICATION FILEDAAUGJZ. 191s.

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WITNESS warren stars rnnr carton JOHN F. JOHNSON, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO PITTSBURGH PLATE GLASS COMPANY, A CORPORATION OF PENNSYLVANIA.

CEMENT- GUN APPARATUS.

Specification of Letters Patent.

Patented Apr. 24:, 191?.

Application filed August 22, 1916, Serial No. 116,248;

apparatus used to spray layers of hydraulic cement upon various surfaces, and in this particular case for spraying layers of plaster of Paris upon grinding tables to support and bind plate glass thereon during the process of grinding and polishing, and has for its principal objects, the provision of a simple inexpensive and eflicient apparatus that may be readily controlled at the nozzle which may be a great distance from the receptacle containing the cement or plaster of Paris; the provision of a cement gun which may be controlled, and a predetermined mixture of the ingredients maintained by means of a single controlling-valve; the provision of a cement gun wherein a plurality of nozzles may be supplied from a central cement receptacle, and the discharge of cement from any nozzle instantly cut off independently of the action of the other nozzles; the provision of an apparatus wherein the nozzles may be cleaned and kept clean 7 while the apparatus is not in use, and such other objects as may hereinafter a pear.

As herein used, the term cement applies to any formof material that may be mixed with water or other liquids to form a plastic mass regardless of whether it subsequently hardens or not, and the term cement gun relates to any form .of apparatus for handling the above ingredients.

In the practice of laying plate glass upon the grinding tables with the use of cement applied with a cement gun, it has been found desirable to provide a plurality. of hydrating nozzles supplied with cement from a single cement receptacle. The receptacle is installed in a central location with the operating valves and mechanismadjacent the receptacle, while the discharge nozzles are connected to the receptacle by long sections of hose and each nozzleis provided with a single controlling valve which controls both the water and cement supply.

One embodiment of the invention is illustrated 1n the accompanying drawings, where1n Figure 1 is a side elevationof the appav ratus showing certain portions in section, and Fig. 2 is alongitudinal section of the air valve operating mechanism.

Referring to the drawings, the apparatus comprises a receptacle 1 of the well known type used in cement guns, for containing a quantity of comminuted plaster of Paris or other substances adapted to form a homogeneous masswhen hydrated. The receptacle is provided with a removable air tight lid, not shown, which fits into the funnel shaped flange 2 at the top of the receptacle. At the bottom of the receptacle is a rotary disk 3 having pockets 4 adapted to receive powdered plaster of Paris. As the disk 3 rotates the powder inthe pockets is moved directly under the air blast nozzles 5 which direct a blast of air downward through the pockets and out through a series of orifices 6 into discharge passages 7 leading to the hydrating nozzles 8, one of which is shown in Fig. 1.

This much of the apparatus is a well known structure commonly used in cement gun apparatus and no claim is'made to the receptacle for the cement or plaster of Paris. It is the purpose of this invention to provide improved means for controlling the deliver of the cement through a hydrating nozz e through the operation of a valve carried at the nozzle which may be a couple hundred feet away from thecement receptacle. It is also the purpose to provide a valve for controllin the discharge of the cement at a point adJacent the receptacle, so that the connecting passage between i the valve and the receptacle'is as short as possible. It has been found that where the valve controlling the cement passage is located at agreat distance from the cement receptacle the passage has a tendency to fill with powdered cement and become clogged so that considerable difiiculty has 'been experienced in freeingv the passage of packed cement. Means are provided 1n this apparatus whereby the valve controlling the ocment passage is controlled by a single valve carried adjacent the nozzle.- The arrangement of valves and piping to accomplish these ends is as follows.

Air under compression is supplied to the cement receptacle through a supply pipe 9. This pipe leads to a sphincter valve 10 to be hereinafter fully described, which serves to close the discharge passage leading from the cement receptacle. From the sphincter valve the air pipe 9 continues and leads to an air valve '10 which serves to cut off the supply of air from the supply pipe to the discharging from the air blast nozzle 5 carries the powdered plaster of Paris or cement into the discharge passage 7 through the sphincter valve 10 and hydrating nozzle 8 which may be of any suitable type.

The plaster of Paris is hydrated by water supplied to the nozzle through the watersupply tube 14, and between the source of water supply and the nozzle 8 is located a pressure operated valve or'motor 15 to be.

hereinafter described. This valve is for the purpose of operating the air valve 10' when changes of pressure occur in the water tube 14. The water tube 14 is connected to the nozzle by means of a flexible tube 16 and the water supply is controlled by a globe valve 17 arranged adjacent the nozzle 8.

A by-pass 18 isprovided in the water supply passage 14 for the purpose of conducting water to the nozzle without passing through the. motor 15 and is for the purpose of supplying water to the nozzle to clean it when the apparatus is not in use. A globe .valve 19 regulates the water passingthrough the by-pass and the valve is so adjusted that it permits just sufiicient water to pass through the tube 16 to clean the nozzle without affecti'ng the operation of the motor 15. Therefore, the valve 17 may be opened slightly without having any operating effeet on the motor 15. The by-pass 20 leads from the air supply 9 to a point in the pas: sage 7 between the nozzle 8 and the sphincter valve 10 for the purpose of maintaining a.

blast of air through the passage 13 so that it will be kept free from powdered cement when the machine is not in operation. The passage of air through the by-pass 20 is controlled by the globe valve 21 which may be set to permit the desired quantity of air to flow through the by-pass. The by-pass 20 is also provided with a check valve 22 for the piston from the plug 25. This action preventing any back-flow of air or cement into the air passage 9.

The motor 15 consists of a cylinder 23 in which is mounted a piston 24. The lower end of the cylinder 23 is closed and carries a tapered valveplug 25 upon spiders 26 integral with the end of the cylinder 23. The piston 24 is provided with a central tapered passage 27 into which the plug 25 projects when the piston 24 is in its lowermost position. A spring 28 normally holds the piston 24 down so that the plug 25 completely stops the passage 27. The piston 24 is provided with a small passage 29 leading therethrough to permit the gradual passage of water from one side of the piston to the other. When the globe valve 17 is open the reduced pressure of the water on the upper side of the piston permits the water under full pressure on the under side of the piston to move the valve 24 upward against the pressure of the spring 28. When the piston '24 moves upward the passage 27 is gradually opened'on account of the separation of permits water to flow from the water tube 14, past the piston 24, out through the passage 14' and flexible tube 16, through the valve 17 into the nozzle 8, where it mixes with the powdered plaster of Paris or cement. e

The piston 24 carries on its upper side a rod 30, which is adapted to engage a valve stem 31 projecting downward from the air valve 10 which may be any well known type 1 of disk valve. When the valve stem 31 is raised it causes the valve 10' to open, permitting the passage of air from the air supply pipe 9 tofthe branches 11 and 12. The

quantity of air passing through the passage 11 is regulated by the globe valve 32 which is set to supply any required amount of air to the top of the cement receptacle.

The sphincter valve 10 comprises a casing 33 in which is secured a piece of rubber tubing 34. This tubing is a continuation of the passage 7 and is joined thereto by means of flanges 35 and 36 secured to the ends of the tubing 7. The ends of the casing 33 are jointed to the flanges 35 and 36 and between 5 the flanges 35 and 36 and the casing 33 is mounted a pair of metallic packing rmgs 37 which are adapted to engage the interior walls of the tube 34 and expand the ends thereof outward against the flared end walls of the casing 33.

When the air valve 10' is closed the pressure in the supply pipe 9 is sufflcient to cause the rubber tube 34to collapse, as indicated by the dotted lines A, thereby closing the passage of cement and air through the discharge tube 7. When the valve 10 is open the pressure inthe tube 9 will be reduced and the pressure in the discharge tube 13 increased so that the flexible tube 34 will asnaaeeee sume its original 0 lindrical shape permitting the free flow o cement and air through the discharge tube 7.

The spring 28 in the motor 15 is of such tension that it will permit the piston 24 to rise in a degree proportional to the opening of the valve 17. Therefore, the openin of the valve 10 effected by the operation 0 the piston 24, will be proportional to the degree of opening in the water valve 17. It will be seen from the foregoing that after the spring 28 is properly adjusted the proportion of water and air'and cement delivered to the nozzle 8 will remain the same regardless of the degree of opening of the valve 17. Therefore, the valve 17 serves to regulate the velocity and quantity of hydrated plaster of Paris delivered from the nozzle.

The operation of the apparatus is as follows: The receptacle 1 is placed at a central location so that it can supply a plurality of nozzles which may be a couplehundr'ed feet away from the receptacle. When the machine is not in operation a small quantity of water is flowing through the by-pass 18 out through the valve 17, into the nozzle, and a small quantity of air is being supplied through the by-pass 20, the air passing through the passage 7 into the nozzle 8 where it mixes with the water and serves to keep the nozzle free of deposits of cement. When it is desired to spray the hydrated plaster of Paris upon the grinding tables, the valve 17 is further opened, which action causes the piston 24 in the motor to be moved upward by the water pressure on the underside thereof, permitting a flow of water past the piston through the passage 14' and flexible tube 16 to the nozzle. The lifting of the piston 24 also moves the valvestem 31, which opens the valve 10 permitting the flow of air through the receptacle. This action reduces the pressure around the tube 34 in the sphincter valve and permits the tube 34 to expand so that a mixture of compressed air and powdered plaster of Paris may be discharged through the discharge passage 7 and delivered to the nozzle 8,

- where it is thoroughly mixed with the water and is discharged onto the table in the form of a spray.

When a suflicient quantity of plaster .of Paris has been deposited upon the table and it is desired to-stop the operation of the device, valve 17 is closed causing the pressure on the upper side of the piston 24 to become the same as on the lower side thereof when the spring 28 will force the piston downward into its lowermost position, thereby shutting off the passage of water through the opening 27 in the piston 24.

When the piston 24 moves downward the air valve 10 will be closed by a spring (not shown) on the upper side of the valve disk in the valve 10, thereby closing the flow of air through the supply passage 9. The instant the air valve 10 closes the pressure around the flexible tube 34 in the sphincter valve 10 will cause the tube to collapse, thereby closing the discharge passage 13. One particular function of the sphincter valve is to cause the supply of plaster of Paris and air to be immediately shut ofi' after the valve 17 is closed, because if the sphincter valve were not present the accumulated pressure in the receptacle 1 would continue to blow dry powder out of the hydrating nozzle 8 after the waterhad been shut ofi. Where a number of nozzles are being operated at the same time, it will be seen that there will be a constant fiow of air into the receptacle 1, and it is necessary to close the discharge passage 13 when it is desired to stop the operation of the machine.

It is desirable that the passage 7 between the receptacle 1 and the sphincter valve 10 be as short as it is possible to make it, so that when the sphincter valve is closed there cannot be an extended accumulation of powder in the passage. It has been found that where the passage 7 is of considerable length between the receptacle 1 and the sphincter valve 10 the passage becomes filled with packed powdered plaster of Paris which is very difiicult to remove from the passage. Another advantage in having this sphincter valve 10 adjacent the receptacle is that the pipe 9 between the sphincter valve 10 and the branch pipes 11 and 12 may be short, thereby saving considerable tubingand making it possible to arrange all operating elements adjacent the receptacle.

After the controlling valve 17 has been closed to stop the passage of the cement through the tube 7, the valve 17 may be left open a little to permit water passing through the by-pass 18 to flow into the nozzle and flush it free of any particles of cement that may remain therein after the passage 7 'has been closed. A small quantity of air is always flowing through the by-pass 20 and through the nozzle 8 which insures a discharge of any cement that may remain in the tube 7. It will be seen that with this arrangement the nozzle will be kept free of particles of cement when the machine is not in operation.

It is obvious that many changes may be made-in the details of the construction without departing from the spirit of the invention, and the invention is, therefore, not limited to the specific construction herein illustrated and described.

What I claim is:

1. The combination with a cement gun having a hydrating nozzle supplied with ingredients through. separate passages, of means controlled by the flow of material through one passage for regulating the flow of material through the other passages.

2. The combination with a cement gun having a hydrating nozzle supplied with fluids through separate passages, of means controlled by the flow of fluid through one passage for regulating the flow of fluid through the other passage.

3. The combination with a cement gun having a hydrating nozzle supplied with water and air through separate passages, of'

means controlled by the flow of water through one passage for regulating the flow of air through the other passage.

4:. The combination with a cement gun having a hydrating nozzle supplied with water through one passage and with a mixture of powdered cement and air through another passage, of means controlled by the flow of water through one passage for regulating the flow of the cement and air through the other passage.

5. The combination with a cement gun having a hydrating nozzle supplied with water through one passage and with a mixture of powdered cement and air through another assage, of means controlled by the flow 0% water through one passage for proportioning the flow of cement and air through the other passage with respect to the flow of water.

6. The combination with a cement gun having a hydrating nozzle supplied with water through one passage. and with a mixture of powdered cement and air through another passage, of means controlled by the fluid passing through one passage for maintaining a predetermined proportion of the one of the tubes controlled by the pressure that tube for regulating fluid through the other tube.

8. A'cement gun comprising in combinathe passage of tion, a receptacle for comminuted cement,

a hydrating nozzle, a tube for conducting water to the nozzle, a tube for conducting cement from the receptacle to the nozzle, fluid means forforcing the cement from the receptacle through the cementtube to the nozzle, and means in communication with the water tube controlled by the pressure in that tube for regulating the passage of.

the cement conducting fluid through the cement conducting tube. 2

9. The combinationlwith a cement gun having a closed receptacle for the cement supplied with compressed air passing through the'receptac'le and forcing cement from a nozzle, a valve for closing the air supply to the receptacle, and a valve between the receptacle and the nozzle adapted to be actuated by pressure in the air supply for closing the passage to the nozzle.

10.'In combination with a cement gun having a closed receptacle for the cement, an air.supply passage leading into the cement receptacle for supplying air under compression, a discharge passage leading from the receptacle through which the cement is discharged by the air pressure within the receptacle, a valve for closing the air supply passage and a valve actuated by the pressure in the air supply passage for closing the discharge passage when the air supply passage is closed.

11. In combination with a cement gun having a closed receptacle for the cement, an air supply passage leading into the cement receptacle for supplying air under compression, a discharge passage leading from the receptacle through which the cement is discharged by the air pressure within the receptacle, a valve for closing the air supply passage and a valve comprising a collapsible tube forming a portion of the discharge passage adapted to be collapsed to close the discharge passage by air pressure in the supply passage when the valve in the supply passage is closed.

12. In combination with a cement gun having a closed receptacle for the cement supplied with compressed air through a plurality of supply passages leading into the receptacle for supplying air under compression to a plurality of discharge passages, means whereby cement is forced from the receptacle through the discharge passages, a valve for closing each supply passage, and a pressure actuated valve in each discharge passage controlled by pressure in a .certain supply passage for closing the discharge passage when the valve in that certain sup- 7 ply passage has been closed.

13. In combination in a cement gun, a receptacle for comminuted cement, an air in- -let passage for supplying compressed air to the interior of the receptacle, a hydrating nozzle, an outlet passage for conducting comminuted cement and the compressed air to the hydrating nozzle, a water passage leading to the nozzle, a valve in the water supply adjacent the nozzle, a valve in the air supply passage, and a motor for operating the air valve actuated by the water in the water passage adapted to close the air valve when the valvecontrolling the water supply is closed.

14. A cement gun comprising in combination, 'a receptacle for comminuted cement, a

hydrating discharge nozzle, disposed at a distance from the receptacle and connected to the receptacle by means of a discharge tube, fluid means for conducting the cement from the receptacle to the nozzle, a tube for supplying Water to the nozzle, a valve adjacent the nozzle for regulating the Water supply, and a valve adjacent the receptacle controlled by the pressure in the Water tube for closing the discharge tube.

15. A cement gun comprising in combination, a receptacle for the cement, a hydrating nozzle, a discharge passage for conducting the cement to the nozzle, a Water passage for conducting'water to the nozzle, a valve for closing the discharge passage, a pressure actuated motor in the Water passage for controlling the valve in the discharge passage, a by-pass in the water tube extending around the motor to permit water to flow directly through the passage to the nozzle, and a means adjacent the nozzle for regulating the passage of water to the nozzle.

16. The combination with a cement gun having a hydrating nozzle supplied with water and air through separate Water and air passages controlled by separate valves, located between the sources of supply and the nozzle, of by passes arranged in the passages between the sources of supply and the nozzle whereby water and air is supplied to the nozzle to clean it When the said valves are closed.

17. The combination with a cement gun having a closed receptacle for the cement supplied with compressed air passing through the receptacle and forcing cement from a nozzle, a valve for closing the air supply to the receptacle, and a Valve between the receptacle and the nozzle adapted to be controlled by pressure in the air supply for closing the passage to the nozzle.

JOHN F. JOHNSON. 

